Things You'll Need
4 millimeter or thicker plastic bags
1 1/2 lb gel ice packs
Sturdy foam insulated boxes
Frozen fish will stay frozen outside of a refrigerator for 1-2 days if it is packed correctly for shipping. During transit there is no guarantee what a package of frozen fish will go through. Frozen fish needs to be sealed air-tight and accompanied by gel ice packs to be fully prepared for the journey. Give frozen fish the best possible chance at arriving still fresh at its final destination by taking a few basic precautions.
Vacuum seal the frozen fish into 4 millimeter or thicker plastic bags. Thinner bags can be punctured by the frozen fish and may leak. Air-tight vacuum sealing containers are another option, but they are more expensive.
Set one frozen solid gel ice pack inside a sturdy foam insulated box for every 20 pounds of fish you are shipping. The foam insulation slows the melting of the gel ice pack and keeps fish frozen. Shipping times are always estimated and it may be as many as three days before the fish reaches its final location.
Set the sealed bag of frozen fish on top of the gel ice packs and cover it with a 2-3 layers of bubble wrap to further insulate and keep the fish from rattling around. Do not substitute frozen water for cold gel packs.
Seal the fish filled box with strong shipping tape to avoid breakage and leaks while being shipped. Write "KEEP FROZEN" in large, bold, easy-to-read letters on the outside of the box to caution handlers that the package is cold.
Ship the package of frozen fish overnight or via two day air through any reputable carrier. Contact UPS, FedEx or the United States Postal service for rates by weight. See link in resources to determine cost to ship with UPS.
Dry ice is more dangerous to handle and commonly more expensive than the gel ice packs. Some shipping companies have set limits as to how much dry ice you can use in a shipment.